Question

I am fresh to spring boot and currently facing this error in STS

"Error creating bean with name 'employeeDao': Unsatisfied dependency expressed through field 'sessionfactory'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException"
Entity Class

@Entity
@Table(name = "studenttable")
public class Employee {



@Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    private Long id;
    @Column(name = "sname")
    private String sname;
    @Column(name = "scourse")
    private String cname;
    @Column(name = "sfee")
    private Double fee;
Hibernate Utils Class
    @Configuration
    public class HibernateUtilsConfig {

        @Autowired
        private EntityManagerFactory entityManagerFactory;

        @Bean
        public SessionFactory getSessionFactoty() {
            if(entityManagerFactory.unwrap(SessionFactory.class)== null) {
                throw new NullPointerException("Factory Not Found");
            }
            return entityManagerFactory.unwrap(SessionFactory.class);
        }
DAO Class
@Repository
public class EmployeeDao {

    @Autowired
    private SessionFactory sessionfactory;

    public void createEmployee(Employee employee) {
        Session session = null;
        try {
            session = sessionfactory.openSession();
            session.beginTransaction();
        Integer id=(Integer)    session.save(employee);
        System.out.println("The record is add in the system" + id);
            session.getTransaction().commit();
        }catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }
    }
Main Class
@SpringBootApplication
public class SpringExampleApplication implements CommandLineRunner {

    @Autowired
    private EmployeeDao employeeDao;

    public static void main(String[] args) {
        SpringApplication.run(SpringExampleApplication.class, args);
    }
    @Override
    public void run(String... args) throws Exception {
        Employee employee = getEmployee();
        employeeDao.createEmployee(employee);

    }
    private Employee getEmployee() {
        Employee employee = new Employee();
        employee.setSname("Imran");
        employee.setCname("Java");
        employee.setFee(1000d);
        return employee;
    }

**Error Log**

org.springframework.beans.factory.UnsatisfiedDependencyException：创建名称为springExampleApplication的bean时出错：通过字段'employeeDao'表示的不满足的依赖关系；嵌套的异常是org.springframework.beans.factory.UnsatisfiedDependencyException：创建名为“ employeeDao”的bean时出错：通过字段“ sessionfactory”表示的不满足的依赖关系；嵌套异常为 org.springframework.beans.factory.UnsatisfiedDependencyException：创建名称为'hibernateUtilsConfig'的bean时出错：通过字段'entityManagerFactory'表示的不满足的依赖关系；嵌套的异常是org.springframework.beans.factory.BeanCurrentlyInCreationException：创建名称为'getSessionFactoty'的bean时出错：当前正在创建请求的bean：是否存在不可解析的循环引用？在org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor $ AutowiredFieldElement.inject（AutowiredAnnotationBeanPostProcessor.java:596）〜[spring-beans-5.1.8.RELEASE.jar：5.1.8.RELEASE]中在org.springframework.beans.factory.annotation.InjectionMetadata.inject（InjectionMetadata.java:90）〜[spring-beans-5.1.8.RELEASE.jar：5.1.8.RELEASE] 在org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties（AutowiredAnnotationBeanPostProcessor.java:374）〜[spring-beans-5.1.8.RELEASE.jar：5.1.8.RELEASE] 在org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean（AbstractAutowireCapableBeanFactory.java:1411）〜[spring-beans-5.1.8.RELEASE.jar：5.1.8.RELEASE] 在org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean（AbstractAutowireCapableBeanFactory.java:592）〜[spring-beans-5.1.8.RELEASE.jar：5.1.8.RELEASE] 在org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean（AbstractAutowireCapableBeanFactory.java:515）〜[spring-beans-5.1.8.RELEASE.jar：5.1.8.RELEASE] 在org.springframework.beans.factory.support.AbstractBeanFactory.lambda $ doGetBean $ 0（AbstractBeanFactory.java:320）〜[spring-beans-5.1.8.RELEASE.jar：5.1.8.RELEASE] 在org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton（DefaultSingletonBeanRegistry.java:222）〜[spring-beans-5.1.8.RELEASE.jar：5.1.8.RELEASE] 在org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean（AbstractBeanFactory.java:318）〜[spring-beans-5.1.8.RELEASE.jar：5.1.8.RELEASE] 在org.springframework.beans.factory.support.AbstractBeanFactory.getBean（AbstractBeanFactory.java:199）〜[spring-beans-5.1.8.RELEASE.jar：5.1.8.RELEASE] 在org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons（DefaultListableBeanFactory.java:845）〜[spring-beans-5.1.8.RELEASE.jar：5.1.8.RELEASE] 在org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization（AbstractApplicationContext.java:877）〜[spring-context-5.1.8.RELEASE.jar：5.1.8.RELEASE] 在org.springframework.context.support.AbstractApplicationContext.refresh（AbstractApplicationContext.java:549）〜[spring-context-5.1.8.RELEASE.jar：5.1.8.RELEASE] 在org.springframework.boot.SpringApplication.refresh（SpringApplication.java:742）上[spring-boot-2.1.6.RELEASE.jar：2.1.6.RELEASE] 在org.springframework.boot.SpringApplication.refreshContext（SpringApplication.java:389）上[spring-boot-2.1.6.RELEASE.jar：2.1.6.RELEASE] 在org.springframework.boot.SpringApplication.run（SpringApplication.java:311）上[spring-boot-2.1.6.RELEASE.jar：2.1.6.RELEASE] 在org.springframework.boot.SpringApplication.run（SpringApplication.java:1213）上[spring-boot-2.1.6.RELEASE.jar：2.1.6.RELEASE] 在 org.springframework.boot.SpringApplication.run（SpringApplication.java:1202）[spring-boot-2.1.6.RELEASE.jar：2.1.6.RELEASE] 在com.imran.works.SpringExampleApplication.main（SpringExampleApplication.java:18）[classes /：na] 造成原因： org.springframework.beans.factory.UnsatisfiedDependencyException：创建名称为'employeeDao'的bean时出错：通过字段'sessionfactory'表示的不满足的依赖关系；嵌套的异常是org.springframework.beans.factory.UnsatisfiedDependencyException：创建名称为“ hibernateUtilsConfig”的bean时出错：通过字段“ entityManagerFactory”表示的不满足的依赖关系；嵌套的异常是org.springframework.beans.factory.BeanCurrentlyInCreationException：创建名称为'getSessionFactoty'的bean时出错：当前正在创建请求的bean：是否存在不可解析的循环引用？在org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor $ AutowiredFieldElement.inject（AutowiredAnnotationBeanPostProcessor.java:596）〜[spring-beans-5.1.8.RELEASE.jar：5.1.8.RELEASE]中在org.springframework.beans.factory.annotation.InjectionMetadata.inject（InjectionMetadata.java:90）〜[spring-beans-5.1.8.RELEASE.jar：5.1.8.RELEASE]

请帮助我

谢谢！

Answer 1

您面临的问题归因于您提供的HibernateUtilsConfig.java配置类。在EmployeeDao类中，您正在自动装配sessionfactory bean。因此，当springboot尝试自动装配bean时，它将失败并显示以下错误：

Unsatisfied dependency expressed through field 'sessionfactory'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'hibernateUtilsConfig': Unsatisfied dependency expressed through field 'entityManagerFactory'; nested exception is org.springframework.beans.factory.BeanCurrentlyInCreationException: Error creating bean with name 'getSessionFactoty': Requested bean is currently in creation: Is there an unresolvable circular reference?

如果entityManagerFactory bean不可用。

由于使用的是spring-boot，因此可能无法手动配置所有内容。您可以通过添加以下依赖项来使用spring-boot中的默认自动配置：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>

然后，您可以在application.properties或application.yml中提供适当的密钥，并且spring-boot将为您配置所有内容。

application.properties

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.username=mysqluser
spring.datasource.password=mysqlpass
spring.datasource.url=jdbc:mysql://localhost:3306myDb?createDatabaseIfNotExist=true

如果您仍然想手动设置所有内容，请尝试创建实体管理器bean，如：

   @Bean
   public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
      LocalContainerEntityManagerFactoryBean em 
        = new LocalContainerEntityManagerFactoryBean();
      em.setDataSource(dataSource());
      em.setPackagesToScan(new String[] { "com.example.persistence.model" });

      JpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
      em.setJpaVendorAdapter(vendorAdapter);
      em.setJpaProperties(additionalProperties());

      return em;
   }

参考documentation。

通过“ employeeDao”字段表示不满意的依存关系；

1 个答案: